Hoist Mechanical Brake; Release Brake Current; Activate Brake Speed; Activate Brake Delay - Danfoss VLT AutomationDrive FC 302 Programming Manual

Parameter Descriptions

2-20 Release Brake Current

Range: Function:
Size [ 0 - Set the motor current for release of the
related par. mechanical braking when a start condition
*
16-37 A] is present. The default value is the
maximum current the inverter can provide
for the particular power size. The upper
limit is specified in parameter 16-37 Inv.
Max. Current.
NOTICE
When mechanical brake control
output is selected, but no mechanical
braking is connected, the function
does not work by default setting due
to too low motor current.
2-21 Activate Brake Speed [RPM]
Range: Function:
Size [ 0 - par. Set the motor speed for activation of the
related 4-53 RPM] mechanical braking, when a stop
*
condition is present. The upper speed
limit is specified in
parameter 4-53 Warning Speed High.
2-22 Activate Brake Speed [Hz]
Range:
Size related [ 0 - 5000.0
*
Hz]

2-23 Activate Brake Delay

Range: Function:
0 s [0 - Enter the brake delay time of the coast after ramp-
*
5 s] down time. The shaft is held at 0 speed with full
holding torque. Ensure that the mechanical braking
has locked the load before the motor enters coast
mode. See Mechanical Brake Control section in the
design guide.
To adjust transition of the load to the mechanical
braking, set parameter 2-23 Activate Brake Delay and
parameter 2-24 Stop Delay.
Setting of brake delay parameters does not affect
the torque. The frequency converter does not
register that mechanical braking is holding the load.
After setting parameter 2-23 Activate Brake Delay, the
torque drops to 0 after a few minutes. The sudden
torque change leads to movement and noise.
MG33MP02
Programming Guide
Function:
Set the motor frequency for
activation of the mechanical
braking when a stop condition is
present.
Danfoss A/S © 10/2018 All rights reserved.
2-24 Stop Delay
Range: Function:
0 s [0 - 5 Set the time interval from the moment when the
*
s] motor is stopped until the brake closes.
To adjust transition of the load to the mechanical
braking, set parameter 2-23 Activate Brake Delay and
parameter 2-24 Stop Delay.
This parameter is a part of the stop function.
2-25 Brake Release Time
Range: Function:
0.20 s [0 - 5 s] This value defines the time it takes for the
*
mechanical brake to open. This parameter
must act as a timeout when brake feedback is
activated.

3.3.4 Hoist Mechanical Brake

The hoist mechanical brake control supports the following
functions:
•
2 channels for mechanical braking feedback to
offer further protection against unintended
behavior resulting from broken cable.
•
Monitoring of mechanical braking feedback
throughout the complete cycle. This helps protect
the mechanical brake, especially if more
frequency converters are connected to the same
shaft.
•
No ramp-up until feedback confirms that
mechanical brake is open.
•
Improved load control at stop. If the value of
parameter 2-23 Activate Brake Delay is too low,
Warning 22 Hoist mech. brake is activated and the
torque is not allowed to ramp down.
•
The transition when motor takes over the load
from the brake can be configured.
Parameter 2-28 Gain Boost Factor can be increased
to minimize the movement. To achieve smooth
transition, change the setting from the speed
control to the position control during the
changeover.
- Set parameter 2-28 Gain Boost Factor to
0 to enable position control during
parameter 2-02 DC Braking Time. This
enables parameter 2-30 Position P Start
Proportional Gain to
parameter 2-33 Speed PID Start Lowpass
Filter Time, which are PID parameters for
the position control.
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